Electrical switch gear



biatch 15, 1932. D, R DAVlEs 1,849,224

ELECTRICALSWITCH GEAR Filed Deo. 28, 1927 Patented Mar. 15, 1932 vUNITED STATES PATENT oFElcE DAvID RECINALD DAvIEs, or DIDSBURY, NEAR MANCHESTER ENGLAND, AssIGNoR To WEs'rINCIIoUsE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION or PENNSYLVANIA ELECTRICAL SWITCH GEAR Appueaan mera December as, 1927, semi No. 243,087, nein Great Dritmeoctober 9, 192s.

This invention relates to electrical switch gear which comprises one or more sets of bus-bars, a circuit breaker for connecting said bus-bars to a cable, isolating switches l for said circuit breaker, and one or more cur-4 rent transformers such as for instruments v 2C, tors eflect'the electrical connectionbf the current transformers with other conductors of the switch gear, for instance with the conductors of the cable after 'trifurca'tion' 0I division and with theleads of the oil switch so that the casing 'containing` thecurrent transformers maybe removed Vwithout disturbing the insulating compound inleither the transformer casing or the cabledividing or trifurcating box or other electrically aol-V jacent casing orcasings." 4

One 'particular arrangement of lswitchgear of the type specified and to which the present invention can be applied, is illustrated in and described with reference to Fig.

1 of the drawings of 'the copending application, Serial No. 70,547 and reference may be .had to'this said application for supplementing the following description with referencev to the drawing herewith, in which: The single figure illustrates a switchgea-r of generally similar arrangement or layoutbut with the alternative connection feature vforming the vsubject of the aforesaid application omitted, whilst certain members of the v switchgear which'per se form no part of the 1 present invention are not shown in detail. The accompanying drawing represents by way of example only oneconvenient embodiment and subsidiary feature of the present 5u invention.

Referring to the accompanying drawing and to Fig. 1 of the aforesaid application, the switchgear illustrated ycomprises in general a framework 1 carrying atfthe `left-hand end, namely, at the rear end of the switchgear, the

lfixed portion 2 of the'latter whilst at ythe right-hand end or front the movable or drawout portions Skis disposed, the latter portion ybeing arranged vto slide horizontally upon rails and being provided with mechanism (not shown) for drawing it in or out with respect to the xedportion 2 ofthe gear, in a manner which per se is well known.

*.The fixed Vportion 2 of the switchgear comprises two compound-filled metal casings 5 and 6 and a compound-filled cable trifurcating box 7, itrbeing assumed that theswitchgear controls a three-phaseelectrical system.

The bus-bar chamber 5 contains three busbars 9. If alternative sets of bus-bars are required an additional bus-,bar chamber sim'- ilarV to the bus-bar chamber 5 may be provided asdescribed inthe aforesaid applica# tion. The bus-bars 9 are respectively conf nected to three sockets 12 disposed in a horizontal plane and located within tubes 11 of insulating material which are Ydisposed with-V l in tubular extensions of the chamber or casing 5 as shown. v

A cable orv feeder 13 entering the trifurcate ing box 7 has three phase conductors 14, which are connectedv respectivelywith the three socket contacts 101. The latter are loy cated in a horizontal vplane in insulatingitubes 102, disposed intubular'extensions103 of e the trifurcatingbox'7 as clearly shown, the arrangement being similar tothe sockets 12 and tubes `11 in the` bus-bar chamber or casing 5.'- As described-in theaforesaid application VSerial No. 70,547 the casing 6 is provided with three socketsfllocated in .insulating tubes 11 disposed in tubular extensions of .the:=casing.` The sockets 16, in accordance with the present invention, are connected with the cable conductors-14 by the plug ccnl tacts 104 located ininsulating'bushings 105 projectingfriomthe fro'ntrface 10,6 of thelow er portion r ofthe casing' 6, the ,plug contacts 104 at their other ends being connected vby lei (IFS

means of conductors 107 with the rear ends of the socket members 16.

The current transformers are located in the casing 6 conveniently upon the bushings 105 which surround the plug contacts 10i and upon bushings 108 which surround the socket contacts 1G, said transformers .being indicated at 10S) and 110 respectively. The casing G may for convenience be split at 111 so that lif necessary access can be had to the transformers by the removal of the rear part of the casing and by chipping away or melt-- ing the compound filling therein. The connectors 107 are conveniently secured by means of nuts so that they can be readily detached if required.,

It will of course be understood that the movable portion 3 of the switchgear com-- prises sets of plug contacts 24 and 29 which are permanently connected to the terminals of the oil circuit breaker 17.

As hereinbefore set forth, it will be appreciated that by reason. of the provision of the co-operating contacts 101 and 104, the casing 6 may be bodily removed from the remaining portion of the switchgear without disturbing the insulating compound and may be replaced by another similar casing.

The potential transformer (not shown) when used is preferably adapted to have a plug and socket connection with the conductors in the transformer casing and may be disposed at the front or the rear of the latter or underneath it as may be found convenient.

It will be understood that various other arrangements of the invention are possible. F or instance, it may equally well be applied to switchgear in which the isolation is effected by vertical movements of a part or parts thereof with respect to fixed portions., similarly the removable chamber may be separable by a vertical movement; the transformers may be located in a chamber which is dissociated from that which carries main isolating switch contacts.

I claim as my invention 1. In an electrical switchgear of the metalclad type, a removable conducting bushing,

\ a metal casing enclosing said bushing and removable therewith, a transformer associated with t-he bushing within the casing, metal-clad electrical conductors, a remova ble metal-clad circuit interrupter, and a portion of a plug-andsocket connection associated with each end of the said bushing and with the said conductors and the said circuit interrupter.

2. An electrical switchgear of the kind de scribed comprising a current transformer housed in a section of metal. casing that is removable from adjacent conductors, a metalclad electrical circuit, a removable metal-clad circuit interrupter, all connected in series and a plug-andsocket connection associated with the ends of said transformer, the electrical circuit and the circuit interrupter, whereby after the circuit interrupter is separated from the electrical circuit and the current transformer, the current transformer and meta-l casing may be separated and removed from the metal-clad electrical circuit.

3. In an electrical switchgear of the metalclad type including a n'ietal-clad circuit7 a removable metal-clad circuit interrupter in series therewith, and a removable metal-clad section positioned between one portion of the circuit and the circuit interrupter, said metalclad section being removable as a unit and including a conductor, a metal casing enclosing the same and solid insulating material between the conductor and the casing.

1. In an electrical switchgear of the metal clad type, the combination of a tri'lurcating box for a three-phase circuit, a removable metal casing enclosing conductors and elec trical apparatus having separable means associated with the trifurcating b :i and a removable metal-clad three-pole circuit interrupter separably associated ith the conductors of the metal casing whereby the casing;l and the circuit interrupter may be selectively removed from the circuit.

5. Electrical switchgear of the metal-clad type including conductors of an electrical circuit, a removable section containingl electrical apparatus separably associated with said conductors and a circuit interrupter separably associated directly with the reniovable section.

6. In electrical switchgear, the combination of a stationary conductor, removable metal casingl containing a second conductor insulated from the casing and also containu in@ a current transformer associated with the second conductor, a iLilug-and-soclict connection for connecting said conductors, a third conductor, a movable circuit breaker having plug-and-soclet connections with the second conductor and the third conductor, whereby said casing carrying the second conductor and the current transformer may be readily removed and replaced. l

In testimony whereof I have hereunto subscribed my name this 12th day of' December,

DAVID REGINALD DAVIES.

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